Opportunity Overview
We are seeking an experienced Director of Nonclinical Development to provide scientific leadership and hands-on execution of nonclinical strategies across our pipeline. This individual will have deep expertise in toxicology, supported by strong capabilities in DMPK and ADME, and a proven track record of delivering high-quality nonclinical packages for regulatory submissions.

The Director will support multiple active programs across a mixed portfolio of small molecules and peptides, spanning IND-enabling through late clinical development. Success in this role requires strong scientific judgment, the ability to operate comfortably in a fast-paced startup environment, and the confidence to contribute an independent scientific perspective in a collaborative and constructive manner. This individual will be an independent self-starter who thrives in a highly collaborative cross-functional team environment.

This role offers broad exposure across development stages, from IND-enabling through registration planning, with meaningful scientific ownership and the opportunity to contribute to data-driven program decisions across a growing pipeline.

Responsibilities and Duties

• Develop and execute integrated nonclinical development strategies (toxicology, DMPK, and ADME) supporting programs from IND-enabling through early and late clinical development, including Phase 3 and NDA planning.
• Serve as the nonclinical development lead on cross-functional program teams, providing scientific input to development strategy, risk assessment, and decision-making across multiple programs.
• Assess nonclinical data packages, identify gaps and risks, and propose mitigation strategies aligned with ICH guidelines, GLP regulations, and evolving global regulatory expectations.
• Propose, design, and oversee nonclinical toxicology, DMPK, and ADME studies at external CROs (GLP and non-GLP), providing scientific oversight of protocols, execution, data interpretation, and final reports, and managing CRO relationships, timelines, and budgets.
• Provide scientific leadership for mechanism-based safety assessment, integrating safety data to inform translational and clinical plans.
• Author, review, and/or substantially contribute to nonclinical sections of regulatory documents, including INDs, IBs, DSURs, NDAs, and other marketing applications, and partner closely with Regulatory Affairs to support health-authority interactions.
• Support preparation for regulatory agency meetings and responses to regulatory questions, with experience representing toxicology/nonclinical functions in interactions with global health authorities (e.g., FDA, EMA).
• Synthesize complex nonclinical data into clear, coherent narratives to support internal decision-making, regulatory filings, and external communications with partners and due-diligence stakeholders.
• Collaborate closely with Clinical Development, Regulatory Affairs, CMC, and Project Management to ensure alignment of nonclinical plans with overall development strategy.
• Operate effectively in a dynamic startup environment, demonstrating flexibility, agility, and the ability to rapidly learn, adapt, and contribute to the evolution of nonclinical standards and ways of working across the organization.

Qualifications and Skills
Required

• PhD, DVM, or equivalent advanced degree in Toxicology, Pharmacology, or a related scientific discipline.
• 10+ years industry experience in nonclinical development within pharmaceutical or biotechnology organizations.
• Deep expertise in toxicology, with strong working knowledge of DMPK and ADME.
• Proven experience delivering nonclinical data packages to support IND-enabling and clinical-stage programs.
• Demonstrated authorship or major contribution to key regulatory documents, including INDs and Investigator's Brochures.
• Extensive experience designing and managing outsourced nonclinical studies and working effectively with CROs.
• Strong written and verbal communication skills, with the ability to synthesize and explain complex data clearly.

Preferred

• Experience contributing to Phase 3 development and/or NDA submissions.
• Exposure to global regulatory submissions or interactions (e.g., EMA, PMDA).
• Prior experience working in an early-stage or startup biotech environment.

This role is based out of our corporate office in Boston, Massachusetts. Rhythm operates in a hybrid-work model. Candidates applying must be willing and able to be in the Boston office in coordination with their department and business needs. This role may involve some travel.

The expected salary range for this position is $182,000 - $275,000. Actual pay will be determined based on experience, level, qualifications, geographic location, and other job-related factors permitted by law. A discretionary annual bonus may be available based on individual and company performance. This role may be eligible for benefits and other compensation such as restricted stock units.